Of course, Christianity is a religion. In fact, it’s the worlds biggest religion.
The expression is meant to distinguish Christianity, to make it holy, to set it apart from what appears to the outside world as mindless RITUALS and STONY/ARBITRARY DOCTRINES. This is true even though all religions have rituals and doctrines, including Christianity.
The term nicely couches Paul’s love chapter. Love’s only application is relationships. Without Love, we are nothing = without relationships, we are nothing.
Relationships are a pre-requisite for love to flourish. Relationships are the container. Love is the contents.
What a God we serve! Amen.